Moisture detection in composites by terahertz spectroscopy

11th International Conference on Damage Assessment of Structures

物理学;材料科学

Malinowski, Pawel^1 ; Palka, Norbert^2 ; Opoka, Szymon^1 ; Wandowski, Tomasz^1 ; Ostachowicz, Wieslaw^1,3

Institute of Fluid-Flow Machinery, Polish Academy of Sciences, 14 Fiszera Street, Gdansk

80-231, Poland^1

Institute of Optoelectronics, Military University of Technology, 2 Kaliski Street, Warsaw, Poland^2

Faculty of Automotive and Construction Machinery, Warsaw University of Technology, 84 Narbutta Street, Warsaw

02-524, Poland^3

关键词: Damage Identification;    Fluid absorption;    Glass fibre reinforced polymers;    Mechanical performance;    Moisture contamination;    Moisture detection;    Reference measurements;    Reflection and transmission;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/628/1/012100/pdf
DOI  :  10.1088/1742-6596/628/1/012100

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The application of Glass Fibre Reinforced Polymers (GFRP) in many branches of industry has been increasing steadily. Many research works focus on damage identification for structures made out of such materials. However, not only delaminations, cracks or other damage can have a negative influence of GFRP parts performance. Previous research proved that fluid absorption influences the mechanical performance of composites. GFRP parts can be contaminated by moisture or release agent during manufacturing, while fuel, hydraulic fluid and moisture ingression into the composite can be the in-service treats. In the reported research authors focus on moisture detection. There are numerous sources of moisture such as post manufacturing NDT inspection with ultrasonics coupled by water or exposition to moisture during transportation and in service. An NDT tool used for the research is a terahertz (THz) spectrometer. The device uses an electromagnetic radiation in the terahertz range (0.1-3 THz) and allows for reflection and transmission measurements. The spectrometer is equipped with moving table that allows for XY scanning of large objects such as GFRP panels. In the conducted research refractive indices were experimentally extracted from the materials of interest (water and GFRP). Time signals as well as C-scans were analysed for samples with moisture contamination. In order to be sure that the observed effects are related to moisture contamination reference measurements were conducted. The obtained results showed that the THz NDT technique can detect moisture hidden under a GFRP with multiple layers.